WEATHER REPORT

Ask Tom Why

March 12, 2009|By Tom Skilling

Dear Tom,

What is the chance that we won't have any more troublesome snowstorms this winter -- say 2 inches or more?

-- Terry Vance

Dear Terry,

The portion of the year during which Chicago can experience snow extends well into the spring, but history tells us Chicago's snow season winds down in March. The likelihood of another significant snowstorm is diminishing with every passing day, but history cautions that it would be premature to put away the snow shovel just yet.

Late-season snowstorms occur at relatively high temperatures and in a moist environment. They produce heavy, slushy snow. The probability of a snowfall of 2 inches or more from this date forward stands at 46 percent, and it does not diminish to 0 percent until May 2. Chicago logged. 3.7 inches of snow on May 1-2, 1940, its latest-ever 2-inch snow.